Those skilled in the art of food processing are cognizant of a variety of devices in which vegetables are exposed to an abrasive surface against which they move or which moves against them to peel the vegetable. One generally conventional feature in such peelers is the use of rotating rollers having an abrasive surface. The vegetables are allowed to traverse the length of a trough or drum defined by a plurality of such rollers, which turn to rub or abrade away the surface of the vegetable. Examples include Savage, U.S. Pat. No. 2,249,787; Wallace, U.S. Pat. No. 3,745,914; Lazzarini, U.S. Pat. No. 3,811,000; Smith, U.S. Pat. No. 3,946,658; Amstad, U.S. Pat. No. 4,062,985; and Magnuson, U.S. Pat. No. 4,132,162. Such peelers are available on the market. Examples include machinery available from A. K. Robins and Company, Incorporated, of Baltimore, Md. and identified thereby as the Magnupeeler, Veg-A-Peel Washer and Peeler, and the Osborn Multi-purpose U-brush Washer. Also similar are the Vanmark Peeler, Model 27, sold by the Vanmark Corporation of Creston, Iowa, and the Bichel/Starr Peeler sold by Ron Bichel and Associates, Inc. of Hustisford, Wis.
In some of the peelers referred to above, the trough of rollers is unobstructed throughout its length. Vegetables simply are dumped in at the intake end of the trough of rollers and migrate to the other end across the generally horizontal set of rollers. In some instances the rollers are made with radially extending bristles canted slightly toward the discharge end of the machine. As a consequence, when a potato or other vegetable impacts against the bristles, it receives a slight impulse or nudge tending to cause it to travel down the trough of rollers towards the discharge end of the machine. Some vegetable peelers are equipped with augers that run the length of the trough to move the vegetables down the trough and regulate the time it takes them to pass through the machine. Examples are the Magnupeeler and the Bichel/Starr Peeler referred to above. A similar structure is seen in Hirahara, U.S. Pat. No. 3,854,395. The Vanmark Peeler referred to above has no auger but instead regulates the discharge of vegetables from the trough of rollers by an adjustable gate that may be manipulated so as partially to block the discharge end of the machine.
An important characteristic of a vegetable-peeling machine is the amount of vegetables it can process in a given length of time. The five machines referred to above as being on the market all receive extensive use in the peeling of potatoes. The skins of the potatoes are commonly loosened by an initial steam treatment. The potatoes then are directed through a peeler, and the skins are removed thereby. Of the machines referred to above, the Osborn Peeler and the Veg-A-Peel are perhaps the simplist and are very similar to each other. Neither has an auger and both have an arrangement of rollers forming a longitudinally extending trough. In the industry, either of these machines is anticipated to be able to peel 12,000 pounds of steam-treated potatoes per hour.
The Vanmark machine is similar to the Osborn and Veg-A-Peel machines in that it has no auger and has rollers forming a trough shape. However, the Vanmark machine also has the gate referred to above capable of partially closing the discharge end with the effect of controlling the flow of potatoes through the machine and building the potatoes into a deeper mass within the machine. The alteration is mechanically simple but the effect is significant. The Vanmark machine is generally thought to be capable of peeling 25,000 pounds of steam-treated potatoes per hour.
The auger-equipped Bichel/Starr and Magnupeeler machines represent further departures from the basic trough of rollers. Each machine has a continuous auger shaft running the length of the trough. On this shaft is mounted an auger that extends inwardly from the discharge end. In the Bichel/Starr machine, the auger extends inwardly into the trough for only part of the trough's length. The auger serves to regulate flow through the machine in much the way that the adjustable gate of the Vanmark machine does. For the rest of the length of the trough, the auger shaft carries a helical ribbon of metal that is continuous with the outer rim of the auger, essentially being an extension of it. Both the auger and the ribbon are of a size such that they sweep the sides and bottom of the trough of rollers as the auger shaft turns. The helical ribbon of metal thus serves to agitate the mass of vegetables in the machine and to provide an additional mechanism to impel vegetables toward the discharge end. It is generally expected by those skilled in the art that the Bichel/Starr machine is capable of peeling 25,000 pounds of steam-treated potatoes per hour.
The auger of the Magnupeeler, in contrast to that of the Bichel/Starr machine, is continuous over the length of the rollers. Thus, whereas the auger of the Bichel/Starr machine terminates part way down the trough of rollers and the helical ribbon of metal continues, the auger of the Magnupeeler simply continues, to extend the entire length of the rollers. In addition, the rollers of the Magnupeeler are arranged to form a complete drum instead of a trough, which drum rotates as the individual rollers also rotate. The Magnupeeler is believed to be substantially similar to the vegetable peeler disclosed in the Magnuson patent referred to above. With its auger and entire rotating drum of turning rollers, the Magnuson device is mechanically more complicated than the other machines referred to. However, the Magnupeeler is expected in the industry to be able to peel 50,000 pounds of steam-treated potatoes an hour.
It will be appreciated that, although physical differences between the machines discussed above are apparent and differences in capacity are marked, it is not known precisely what aspects of each machine contribute in exactly what way to their production capacity. Small differences, such as the adjustable gate of the Vanmark machine, can apparently be responsible for significant differences in capacity. Those skilled in the art are not cognizant of a peeling machine of simple mechancial structure that exhibits the highest capacity.